github: split up test steps

Splitting up the tests ensures that each step runs in the right directory
without having to rely on more complex shell scripting. That failures get
reported separately is an added bonus.

The simpler `(cd hack/tools && go test ./...)` wasn't supported by Windows.

.github/workflows/test.yml

@@ -14,12 +14,14 @@ jobs:
         go-version: ${{ matrix.go-version }}
     - name: Checkout code
       uses: actions/checkout@v2
-    - name: Test
+    - name: Test klog
       run: |
         go get -t -v ./...
         go test -v -race ./...
-        cd hack/tools && go test -v -race ./... && cd ../..
-        cd examples && go test -v -race ./... && cd ..
+    - name: Test hack/tools
+      run: cd hack/tools && go test -v -race ./...
+    - name: Test examples
+      run: cd examples && go test -v -race ./...
   lint:
     runs-on: ubuntu-latest
     steps: